President Trump, according to reporting in the Washington Post, is pleased to learn from special counsel Robert S. Mueller III that he is a subject, not a target of the Department of Justice’s investigations. Should the White House be celebrating?

First we need to get the terminology straight, and in this case, straight from the United States Attorney’s Manual, which is getting more readership from the general public these days than it normally gets from federal prosecutors.

The labels refer to three categories for those who are asked, or summoned, to testify before a federal grand jury.

A “witness” is someone who has useful information but no apparent involvement in a crime. A “subject” is a person whose conduct is within the scope of the grand jury’s investigation — he is not uninvolved, but he is also not for certain involved in a crime. And a “target” is someone against whom there is substantial evidence, a person who “in the judgment of the prosecutor, is a putative defendant.” In other words, a target is likely to be charged.

Back to the president and the Mueller investigation.

For most observers, there is plenty of evidence that could make Trump not just the subject but a target of an obstruction of justice investigation. It includes the contemporaneous notes of former FBI Director James B. Comey and Deputy Director Andrew McCabe about Oval Office pressure to ease up on Russia-related investigations; Trump’s apparent understanding that former national security advisor Michael Flynn had improper contacts with Russia; his shifting account of the reasons for his actions until he told NBC’s Lester Holt he was responding to “this Russia thing”; his fury at Atty. Gen. Jeff Sessions’ recusal from the matter; his many tweets raging at the probe.

And that is just the publicly available evidence. Mueller may have much more from the testimony of Flynn and others, particularly from former White House chief strategist Stephen K. Bannon.

But the Washington Post report suggests that Mueller isn’t persuaded: He apparently told the president he wasn’t a criminal target. How can that be? Has the special counsel gathered exculpatory evidence that we don’t know about? Is there some flaw in the above catalog?

One hypothesis making the rounds focuses on the unusual nature of the probe itself. Justice Department policy precludes the indictment of a sitting president. Instead, Mueller will probably eventually issue a report to the deputy attorney general, Rod Rosenstein, who will decide whether to make it public. That report could very well be the basis of an impeachment referral, but it wouldn’t be an indictment per se. So Trump isn’t a target because Mueller can’t and won’t charge him in criminal court.

This hypothesis, however, fails to take into account Mueller’s deserved reputation for integrity. Telling the president he isn’t a target, but meaning it only in the most technical of ways, is squirrelly, and it’s inconsistent with the special counsel’s straight-shooting character.

For anyone who knows Mueller, a better explanation is this: The special counsel is maintaining an open mind with respect to Trump’s guilt, though to many on the outside of the investigation, the evidence against him is overwhelming.

To prove obstruction of justice, you have to know the mental state of the defendant. It’s a charge based particularly on intent, not just actions. This distinction would apply with special force in the case of a sitting president, who has broad constitutional authority to shut down a criminal investigation such as the Russia probe for any number of legitimate purposes.

Mueller has yet to interview the president, he has yet to hear in detail what he and his lawyers have to say about the matter. If Trump or his lawyers can persuade Mueller (or, more precisely, create a reasonable doubt in his mind) that the president acted for any noncorrupt purpose — even a mistaken or puerile one — Mueller would have to stay his hand.

The news that Mueller does not consider Trump a criminal target probably best translates as follows: I have built a very strong case against you, including strong evidence that you acted corruptly, to safeguard your personal interests. But it’s conceivable that something else was in play, and you should be given a full opportunity to spell this out for me. Until you do, or until you turn down that opportunity, I am keeping an open mind and you are not a target, merely a subject of the investigation.

Trump is quite likely just a hair’s breadth from target status. Moreover, it’s hard to imagine given the available evidence what cogent exculpatory account of his intent the president could actually provide. Mueller’s guidance that Trump is not a criminal target adds up to a glimmer of hope, but little cause for crowing in the Trump camp.